"If quirrel can get a troll into Hogwarts..."
It was not Quirrel, but Dumbledore, who got troll into Hogwards. In analogy to canon, Dumbledore brought a troll to Hogwards as a training device for Harry and Hermione, see the book HP and Philosophers stone. In canon the purpose was fulfilled, because the children had some sparring with troll and defeated him safely afterwards. In HPMOR, the plot is reversed, because neither Harry nor Hermione fall for this training trap. When told they should NOT go to Hogwards basement, because the troll is there, they are immune to the reversed psychology. Rather, they reasonably decide to obey and not to do the dangerous thing. They simply ignore the basement. Dumbledore makes another try later by telling Harry once more NOT to go to the basement and NOT to use the Alohomora spell to unlock the basement door. In vain again. So the troll stays in the basement for a long time, until Quirrel unleashes him, transforms him to be sunlight-immune and uses him as a weapon on Hermione.
http://harrypotter.wikia.com/wiki/Quirinus_Quirrell%27s_first_mountain_troll also you seem to have a very shitty understanding of canon.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 99, 100, and 101. The previous thread is at nearly 500 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system.
Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: